Brain scans may show which criminals are more likely to continue life of crime

Can a criminal's brain scan reveal if he or she is more likely to commit another crime?

A new study published in the Proceedings of the National Academy of Sciences on March 27 revealed that convicts with low-activity in an area of the brain called the anterior cingulate cortex (ACC) were more likely to be arrested again.

The ACC is a small area in the front of the brain that controls motor function and executive functioning, which are skills required for planning, organization and self-control. Researchers looked at 96 male prisoners right before they were released. The subjects' brains were scanned using functional magnetic resonance imaging (fMRI) while they were instructed to do computer tasks where they had to make quick decisions and rely on their impulses. Then, the researchers followed the subjects for four years.

Men who had lower ACC activity had a 2.6 times higher rate of rearrest for all crimes and a 4.3 times higher rate arrest for non-violent crimes.

The authors, however, said that the method isn't reliable for predicting crimes, warning that scanning brains might only mark high-risk felons, leaving the majority of low-risk ones alone. Also, the test hasn't been compared to other written tasks that have been created to try and determine the likelihood a person will commit a crime again. The researchers have scanned 3,000 inmates in New Mexico state prisons and hope to expand their tests.

Tor Wager, a neuroscientist at the University of Colorado in Boulder not involved in the study, told Nature that the ACC is often activated when people are doing all kinds of different tasks and throughout various psychological states. This means that low ACC activity could be caused by other factors like impulsivity, caffeine use, vascular health, low motivation or better neural efficiency.

"A treatment of [these clinical neuroimaging studies] that is either too glibly enthusiastic or over-critical will be damaging for this emerging science in the long run," Wager cautioned.

Other scientists said that the test is promising.

"This is an exciting new finding," said Essi Viding, a professor of developmental psychopathology at University College London, to Wired. He was not involved in the study. "Interestingly this brain activity measure appears to be a more robust predictor, in particular of non-violent offending, than psychopathy or drug use scores, which we know to be associated with a risk of re-offending."